DCP用量对动态硫化POE/PP热塑性弹性体性能的影响

研究了过氧化二异丙苯(DCP)用量对动态硫化乙烯一辛烯共聚物聚丙烯(POE/PP)体系的物理性能以及PP结晶形态和POE相态结构的影响。结果表明:随DCP用量的增加,POE/PP体系的交联密度增大,而断裂伸长率、永久变形和拉伸强度下降。过量DCP的加人会导致PP降解,使体系的熔体流动速率随DCP用量的增加呈上升趋势。DSC分析表明,随着DCP用量的增加,POE/PP体系结晶度下降。微观分析得出,DCP对POE/PP体系相态结构影响显著,当DCP用量为1份时交联POE以较小的颗粒均匀分布于PP连续相中。     

交联改性聚丙烯的研究

以过氧化二异丙苯(DCP)为交联剂,苯乙烯(St)为助交联剂对聚丙烯(PP)进行交联改性。研究了交联剂(DCP)及交联剂(St)的用量对交联PP的力学及结晶性能的影响。结果表明,交联可以改善PP的性能。在DCP用量为0.05%,St为4%时,交联PP冲击强度达到3.83 kJ/m2,比纯PP提高了27%;拉伸强度由纯PP的36.02 MPa升高到37.22 MPa;交联PP的球晶尺寸减小,球晶间的界面模糊。     

交联硫化体系对PP／POE／EPDM热塑性弹性体性能的影响

采用动态硫化法制备聚丙烯／聚烯烃弹性体／三元乙丙橡胶（PP/POE／EPDM）共混型热塑性弹性体,研究了交联前后不同POE／EPDM并用对比体系力学性能的影响。采用交联剂过氧化二异丙苯（DCP）及DCP／S硫化体系对PP／POE／EPDM体系进行硫化,研究了力学性能的变化。结果表明,EPDM可有效降低材料的硬度和断裂永久变形。助交联剂硫黄（S）对PP／POE／EPDM体系有较好的硫化作用,固定DCP用量为3份,S用量为0．4份时,体系力学性能最佳,交联对体系硬度影响很小。     

交联剂和助交联剂对ABS/PP/CaCO3反应性共混的影响

为提高ABS/PP/CaCO3复合材料相容性,采用转矩流变仪观察了ABS/PP/CaCO3三元复合物反应性共混后的扭矩,考察了不同的助交联剂蓖麻油(CO)、异氰脲酸三烯丙酯(TAIC)、松香酯(JS-1)、二甲基丙烯酸乙二醇酯(GD)以及交联剂过氧化二异丙苯(DCP)的用量对共混物的影响.研究结果表明,在交联剂DCP为0.2%(wt)时,助交联剂GD比CO、TAIC、JS-1对ABS/PP/CaCO3体系有更好反应共混效果;反应共混超过2.5 min后,随DCP量增加,复合材料将发生严重的降解.用毛细管流变仪研究了复合材料的流变特性,结果显示用DCP/GD交联体系反应共混的ABS/PP/CaCO3复合材料的剪切黏度,随温度、剪切速率的增加而下降,比较同一剪切速率下的非牛顿指数,说明其流动性能优于纯ABS.力学性能测试数据说明,用DCP/GD交联的ABS/PP/CaCO3复合材料比未交联的有较高的弯曲强度和模量.电镜观察揭示了用DCP/GD动态交联的ABS/PP/CaCO3复合材料有更好的界面相容.     

炭黑对动态硫化POE/PP热塑性弹性体性能的影响

采用动态硫化法制备POE/PP共混物,研究了过氧化二异丙苯（DCP）对POE/PP体系熔体流动速率（MFR）和力学性能的影响。交联助剂硫磺（S）的加入有效地提高了交联效果,当m（DCP）/m（S）=2/0.2时,体系的综合力学性能最佳。通过不同加工工艺制备POE/PP/炭黑共混物,并研究了炭黑用量对体系力学性能和老化性能的影响。结果表明,母料法制备的共混物更有利于炭黑的分散,体系性能更好,炭黑的加入使体系的耐热老化性和抗紫外性能明显改善。     

助交联剂松香酯对聚丙烯交联性能的研究

以过氧化二异丙苯(DCP)为主交联剂,松香酯为助交联剂,采用化学交联法对聚丙烯进行交联改性。分别测试DCP和DCP/松香酯交联体系下,PP的熔体质量流动速率-凝胶含量-抗熔断能力以及力学性能。结果表明,与单独使用DCP相比,DCP/松香酯交联体系使PP抗熔断能力延长了12 min,当DCP为2 phr时,PP的熔体质量流动速率减少了0.1 g/10min,凝胶含量提高了15%,冲击强度和拉伸强度分别增加了0.73 k J/m2、1.97 MPa。     

马来酸酐和苯乙烯接枝改性对天然橡胶/聚丙烯共混物物理机械性能的影响

用动态硫化法制备了天然橡胶(NR)/聚丙烯(PP)热塑性弹性体(TPV)。研究了马来酸酐/苯乙烯/过氧化二异丙苯(MAH/St/DCP)多单体熔融接枝交联改性及纳米二氧化硅用量对NR/PP TPV物理机械性能的影响,讨论了NR/PP TPV的重复加工性能。结果表明,当MAH/St/DCP用量为3.750/1.875/0.375质量份、纳米二氧化硅用量为3质量份时,NR/PP TPV的物理机械性能最好,达到了国内外有关通用橡胶/PP TPV的水平,并且具有较好的重复加工性能。     

硅烷交联PP/POE共混材料的性能研究

采用反应性挤出法制备了硅烷交联聚丙烯/聚烯烃弹性体(PP/POE)共混材料。研究了过氧化二异丙苯(DCP)用量对硅烷交联PP/POE共混材料凝胶含量、热稳定性、结晶行为、耐溶剂性及力学性能的影响。结果表明:随着DCP用量的增加,硅烷交联PP/POE共混材料的凝胶含量、热稳定和耐溶剂性均逐渐提升。随着交联程度的增大,共混材料中PP相的结晶度逐渐减小。扫面电子显微镜(SEM)分析结果显示,硅烷交联反应能够改善PP和POE相之间的相容性。力学性能测试结果显示,相比于未改性PP/POE共混材料,硅烷交联PP/POE共混材料的各项性能均有不同程度的提升。     

动态硫化对SBS/PP热塑性弹性体的影响

采用动态硫化法制备苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)/聚丙烯(PP)热塑性弹性体,研究了硫化体系、硫化剂含量和橡塑比对SBS/PP共混物的力学性能、结晶与熔融行为、热稳定性、耐溶剂性的影响。结果表明,采用硫黄硫化体系弹性体的力学性能要优于采用过氧化二异丙苯(DCP)和酚醛树脂硫化体系的弹性体,且最佳硫化剂用量为1.5份;SBS/PP弹性体的最佳橡塑质量比为80/20;动态硫化使SBS/PP弹性体的结晶温度升高,热稳定性增强,耐溶剂性提高。     

交联剂对动态硫化POE/PP性能的影响

研究了过氧化二异丙苯(DCP)用量对动态硫化乙烯一辛烯共聚物(POE)/聚丙烯(PP)体系的力学性能以及PP晶体结构和POE形态结构特征的影响.结果表明,随DCP用量的增加,体系交联密度和熔体流动速率(MFR)增大,而断裂伸长率、拉伸强度和永久变形呈下降趋势;DCP的加入使PP晶体完善,尺寸变大,而结晶度下降;DCP对相态结构影响显著,用量为1份时交联POE以较小的颗粒均匀分布于PP连续相中,当用量为2份时表现为较好的界面相容性.     

Influences of dicumyl peroxide on morphology and mechanical properties of polypropylene/poly(styrene‐b‐butadiene‐b‐styrene) blends via vane‐extruder

Polypropylene (PP) and poly(styrene‐b‐butadiene‐b‐styrene) block copolymer (SBS) were melt‐blended in the presence of initiator system. Dicumyl peroxide (DCP)/Triallyl isocyanurate (TAIC) via self‐deigned VE, aiming at in situ reactive compatibilization of toughed PP/SBS blend. The reactivity, morphology and mechanical properties of PP/SBS/DCP/TAIC blends were studied. Online torque detection was conducted to monitor changes in viscosities of reactive compatibilized blends, which could give proof of the interfacial grafted reaction induced by DCP/TAIC system. The effect of reactive compatibilization on the dispersed particles sizes and interfacial adhesion was studied by scanning electron microscopy. Analysis on mechanical performance revealed the impact strength improved after treated by initiator system, moreover, the impact‐fractured surface observation showed, the failure mode changed from debonding mechanism of neat 50PP/50SBS blend to plastic deformation mechanism of blend containing 3.0 phr initiator system. With improved interfacial adhesion, compatibilized blends not only were toughened but also exhibited enhanced tensile strength and thermal stability. Dynamic mechanical analysis showed a reduction of between PP phase and the PB segments in SBS phase, indicating reactive compatibilization of the blend was achieved. In the final part, a brief discussion was given about the dominant effects from chain scission of PP matrix to intergrafting reactions of PP and SBS, under different content of DCP/TAIC initiator system. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41543.     

Application of phase dispersion–crosslinking synergism on recycling commingled plastic wastes

A tetra‐component blend, consisting of low‐density polyethylene (LDPE), polyvinyl chloride (PVC), polypropylene (PP), and polystyrene (PS), was studied as a model system of commingled plastic wastes (LDPE/PVC/PP/PS, mass ratio: 70/10/10/10). Effects of chlorinated polyethylene (CPE), ethylene–propylene–diene monomer (EPDM), styrene–butadiene–styrene (SBS), and their mixture (CPE/EPDM/SBS, mass ratio: 2/2/2) on the mechanical properties and morphology of the system were investigated. With addition of several elastomers and their mixture, the tensile strength of the blends decreased slightly, although both the elongation at break and the impact strength increased. Among these elastomers, EPDM exhibited the most significant impact modification effect for the tetra‐component blends. SBS and the mixture have a good phase‐dispersion effect for the tetra‐component blend. By adding a crosslinking agent [dicumyl peroxide (DCP)], the mechanical properties of the tetra‐component blends also increased. When either SBS or the mixture was added to the blend together with DCP, the probability that the crosslinking agent (DCP) would be at the interface improved because of the phase‐dispersion effect of SBS. Therefore, more co‐crosslinked products will form between LDPE and other components. Accordingly, remarkable improvement of the interfacial adhesion and hence the mechanical properties of the tetra‐component blends occurred. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2947–2952, 2001     

动态交联PP/EVA共混物的制备与性能研究

本文将动态交联技术应用于PP/EVA共混体系中,制得动态交联PP/EVA共混物。采用Hakke转矩流变仪研究了动态交联对PP/EVA共混物扭矩的影响;研究了DCP和EVA含量对共混物力学性能的影响;考察了动态交联共混物的维卡软化点。结果表明：加入DCP后,PP/EVA共混物扭矩先升后降,DCP的添加量为EVA含量的1%为宜。随EVA用量的增加,动态交联EVA/PP共混物的冲击强度大幅提高,但拉伸强度有所降低。少量经动态交联的EVA颗粒可以促进共混物中PP的结晶, 提高共混物的维卡软化点。     

PP／HDPE／SBS三元共混物的研究——形态结构与性能

研究了PP/HDPE/SBS三元共混物的性能及形态结构特征。研究结果表明,PP三元共混物的冲击韧性除与SBS的含量密切相关外,还与HDPE的含量有关,HDPE起到了与SBS相似的增韧作用。由于HDPE的掺入,减少了SBS的含量,制成了一种力学性能均衡的超高韧性PP三元共混材料。形态结构的研究表明,共混物中,SBS呈颗粒状分布,另外SBS还与HDPE组成了具有包藏结构的复合粒子。     

DCP对PP/GF/UP复合材料性能的影响

以聚丙烯(PP)及玻璃纤维(GF)为原料,以不饱和树脂(UP)作为界面相容剂,研究过氧化二异丙苯(DCP)含量对玻璃纤维增强PP复合材料力学性能、界面和结晶行为的影响.结果表明:DCP的加入改善了PP/GF/UP复合材料的流动性,复合材料的拉伸、弯曲和冲击性能先上升后下降,且在UP和DCP质量含量分别为5%和0.2%时,出现极大值.随DCP的增加,结晶峰温度先向低温偏移,后向高温偏移,而结晶度变化趋势相反.     

丙烯酸改性卤锑阻燃PP的力学性能

在过氧化二异丙苯(DCF)存在或不存在条件下,制备了丙烯酸(AA)改性Sb2O3／聚丙烯(PP)母料、十溴联苯醚／PP母料及其相应的卤锑阻燃PP。研究了Sb2O3、十溴联苯醚和不同含量卤锑阻燃剂对PP力学性能的影响。结果表明,随Sb2O3含量增加,PP的拉伸和弯曲性能提高,缺口冲击强度降低。对于改性阻燃PP,无DCP时,加入AA有利于阻燃PP拉伸强度提高。但对其他力学性能影响不大。添加DCP提高了PP的弯曲强度。但AA用量高时,缺口冲击强度降低。AA改性阻燃PP的力学性能随着DCP用量增加而降低,尤其缺口冲击强度。退火处理使阻燃PP力学性能提高。     

PP／废旧橡胶／SBS复合材料的制备和力学性能研究

通过磨盘型力化学反应器制备PP/废旧橡胶(WTR)复合粉体，然后与SKS共混制备PP/WTR/SBS复合材料。研究了材料的力学性能、微观结构和共混物的加工性质。结果表明：当SBS添加量在20％～25％时，PP/WTR/SBS复合材料的力学性能较PP/WTR有了很大的提高，当SBS用量为25％时，断裂伸长率提高了365％，冲击强度提高了73．2％，而体系的拉伸强度基本不变。复合材料冲击断面的形貌和复合体系流变性能研究结果表明：磨盘碾磨可有效改善各组分间的混合性能，提高相容性并有效改善材料的加工性能。     

Thermal and mechanical properties of microcellular thermoplastic SBS/PS/SBR blend: effect of crosslinking

This study investigates the effect of peroxide crosslinking on the structure and mechanical properties for SBS/PS/SBR foams composed of polystyrene (PS), poly(styrene-b-butadiene) diblock copolymer (SBR-1502), and poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS). The cell size and its distribution of SBS/PS/SBR foams were investigated by SEM images, showing the smaller and denser of hollow cells for the SBS/PS/SBR foam containing the higher concentration of DCP (dicumyl peroxide). As expected, the density of the SBS/PS/SBR foams increases with increasing the content of DCP. The high density of polymeric foams exhibits the high mechanical properties such as hardness, shrinkage, tensile strength, tear strength, elongation at break, and compression set.     

磺酸钠基苯乙烯-丁二烯-苯乙烯嵌段共聚物离聚体的力学性能及其应用

由环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与NaHSO3开环反应合成了磺酸钠基SBS离聚体。研究了离聚体力学性能的影响因素、离聚体对SBS/氯醇橡胶(CHR)的增容作用、质量比对离聚体/聚丙烯(PP)共混物性能的影响。结果表明:硬脂酸锌能提高离聚体的力学性能;随着离聚体离子含量的增加,拉伸强度及扯断伸长率增加。加入少量离聚体,使离聚体/CHR共混物的力学性能提高,扫描电镜显示两者的相容性增加;离聚体与PP共混,在拉伸强度方面呈现协同效应。质量比各为1/1的离聚体增容SBS/CHR和离聚体/PP共混物的耐油性均较SBS大为改善。